html,body {
    height: 100%;
}
.demos-header {
    padding: 35px 0;
}
.demos-title {
    text-align: center;
    font-size: 28px;
    color: #c5094e;
    font-weight: 400;
    margin: 0 15%;
}
#div_up{
    height:88%;
}